If you were going to write down the most frightening infectious diseases you could think of, measles probably wouldn’t be near the top of your list. Compared with the devastation of HIV/AIDS or the gruesome deaths caused by hemorrhagic fevers like Ebola, measles, with its four-day-long fevers and pervasive rashes, seems like nothing more than an annoyance.

But there is one thing that makes measles unique, and uniquely frightening to public health officials: It is the most infectious microbe in the world, with a transmission rate of around 90 percent. The fact that measles can live outside the human body for up to two hours makes a potential outbreak all the more menacing.

This explains the all-hands-on-deck response when officials with the Massachusetts Department of Public Health learned in late August that two unconnected patients — an infant who’d recently arrived in the United States and a foreign-born adult who’d recently traveled abroad — had visited area hospitals with active measles infections. Identifying the hundreds of people who’d potentially been exposed and then checking their vaccination status required, in the words of Dr. Larry Madoff, director of the state’s Division of Epidemiology and Immunization, a “huge effort” on the part of dozens of state, local, and hospital employees.

Fortunately, there were no secondary infections this time around, a fact that is due in no small part to the impressive vaccine uptake rate in this state. It would be a mistake to assume this will always be the case: Massachusetts is seeing a surge in the number of unvaccinated children. Last year, nearly 1,200 kids entered kindergarten with religious or philosophical vaccine exemptions, roughly double the total about a decade ago.

That mirrors what’s happening across the country. What’s so confounding is that many of the parents requesting exemptions for their children cite specious, disproven fears — such as that the vaccine could cause autism — many of which were based on a fraudulent, retracted study or fringe research published in non-peer-reviewed journals.

SM: It was an atrocious paper, it was called, almost the minute it was published, the worst paper The Lancet has ever published. And we’ve since learned a lot of things that were wrong that we didn’t even know at the time in 1998, like the fact that Wakefield was receiving research money from a law firm that was working with parents who were interested in suing vaccine manufacturers, like the fact that Wakefield had taken out a patent for an alternative measles vaccine several months before the paper was published. But what I think is kind of interesting is, forget all of that, it’s insane to make population-wide conclusions on a 12-person case series. And you know sometimes if I’m talking to a group of people and this comes up, I’ll count off 12 people and say, ‘and based on that case series I’m going to go ahead and conclude that population is 90 percent female or everyone is over the age of 50,’ or whatever.

CSM: The media played a large role in spreading misinformation about vaccines and autism following the publication of Wakefield’s study. Although The Lancetofficially retracted the paper in 2010, the controversy still persists to this day. In fact, just last year, 21.4 percent of respondents in the Thomson-Reuters NPR Health Poll said they believe that vaccines can cause autism. It doesn’t help that well-known figures like Jenny McCarthycontinue to spread anti-vaccine rhetoric. There’s even a website called JennyMcCarthyBodyCount.com. It claims that even though she’s not directly responsible for the thousands of preventable illnesses and hundreds of preventable deaths since 2007, if her campaign against vaccination caused even one preventable death, that’s one too many.

SM: Once you introduce misinformation into a society, it then lives on its own. And, it’s, as we’ve seen with vaccines, it’s impossible to unscare someone. Once an idea is planted in your mind, especially about your children, you can’t just then sort of wipe the board clean, ‘oh it turns out that actually ignore everything we were saying.’

CSM: But we have to learn to wipe the board clean, because there’s no scientific evidence linking vaccines with autism. None. If I left dinner last night and it started to rain, would I avoid that restaurant in the future, fearing that every time I ate there, it would influence the weather? Of course not! Autism symptoms commonly appear in children soon after they’re old enough to get vaccinated. This doesn’t mean they’re connected. And those who refuse to see this may be less likely to vaccinate their own children, putting them at risk of infection. And if their kids don’t get sick, sometimes they see this as proof positive that vaccines aren’t necessary. But what they don’t know is that the reason their kids aren’t getting sick is because all the kids around them are vaccinated. It’s called herd immunity, but it’s only so effective.

SM: I compared it once to like a herd of buffalo, kind of encircling their weakest members to ensure that they don’t get picked off by predators. So when you have enough members of a population protected or who have immunity against a given disease, that disease can’t get a toehold in the community. So you know take measles, which has a 90 percent infection rate, and if you were in a community where there was 95 percent immunity and then you had a traveler from Africa or Europe come over infected with measles, there would be a good chance that you could contain that because it’s going to be hard for measles to spread from person to person because there just aren’t those vectors.

JM: Take a look around. I believe science was wrong yet again. [cheering]

CSM: Do you know someone who still sees a link between vaccines and autism, even though no link exists? Reach out to me on Twitter, Facebook, or leave your comments … on The Huffington Post. Come on, Talk Nerdy To Me!

Antivaccine activists claim that vaccines contain all sorts of terrifying poisons. Is this true? http://infactvideo.com/

Vaccine Ingredients

Antivaccine activists claim that vaccines contain all sorts of terrifying poisons. Is this true?

Antivax conspiracy theorists tell us that vaccines are deadly and contain some extraordinary toxins. Let’s examine a few of these ingredients, starting with:

FORMALDEHYDE: Absolutely true. Formaldehyde is used to sterilize some vaccines. We use formaldehyde for this because it’s found naturally in the human body, as it’s a normal byproduct of metabolism and digestion.

ANTIFREEZE: False. However some vaccines are sterilized with something called 2-phenoxyethanol, which is also used as a topical antibacterial for wounds. This and antifreeze come from the same family of hydrocarbons, but they are not the same thing.

MERCURY: Sort of true. Some vaccines are sterilized with thimerosal, also used in contact lens fluid and many other products. However, it contains mercury bound as an ethyl — the version of mercury that can be dangerous has to be bound as a methyl, which is different.

Vaccine hysteria is a trend of mistrust of vaccination that is almost as old as the technique itself. “Anti-vaxxers”, “vaccine deniers”, or “anti-vaccinationists” blame vaccines, or their ingredients, for a range of maladies whose mechanisms are rejected or have not been explained by current scientific research. Some of these maladies can often be childhood illnesses in order to increase the emotive factor of the argument. The ubiquity of vaccination often makes it an easy target for blame.

Vaccine-preventable diseases have been a major cause of illness, death, and disability throughout human history. The advent of the modern vaccine era has changed this significantly; most North Americans and Europeans have little memory of a pre-vaccine era where diseases such as mumps and measles – to say nothing of smallpox or polio — were common and often deadly.